The proposed research for the coming years includes (a) completion of the investigations of the infant's ability to perceive differences in a series of stimuli that signal either a stop consonant (b) or a nasal consonant (m), (b) to initiate an investigation into the ability of the infant to perceive the distinction between a stop consonant and a semi-vowel, (c) to complete our investigations of whether phonetic segments are perceived as an organized set of distinctive features by the human infant, (d) to continue and extend our investigations of the extent and nature of the dependencies that exist among features during the processing of phonetic segments, (e) to investigate further the operating and tuning characteristics of the channels of analysis for the features of speech, and (f) to continue our efforts to write a theoretical description of the processing of the phonetic segments in speech and the course of development of this ability.